Riot police will stay in place "as long as necessary and until a lasting calm is restored" in the Paris suburb of Trappes, following violent clashes after a woman was stopped by police because she was wearing a full Islamic veil.

French riot police remained on full alert in a Paris suburb Monday following a weekend of violence sparked after police stopped a woman who was wearing a full Islamic veil.

Interior Minister Manuel Valls said police would remain in place “as long as necessary until a lasting calm is restored” in Trappes, a southwestern suburb of Paris.

On Friday night, at least 250 people in Trappes besieged the town’s police station, with video showing rioters hurling fireworks at police officers while a number of bins were set ablaze.

Four police officers were injured and six people detained during the violence. A 14-year-old boy suffered a serious eye injury from a projectile, police said.

The clashes were sparked by the arrest on Thursday of a man accused of assaulting a police officer after his wife was stopped for wearing a full-face veil – illegal in public places under French law.

Prosecutor Vincent Lesclous told reporters that the man had attempted to strangle the police officer during the altercation. Local Muslim groups deny this, and insist he was provoked.

Valls said he did not doubt "for an instant" that the police officers acted with respect towards the woman when conducting their check.

Despite a heavily reinforced police presence, approximately 50 people were involved in fresh clashes with riot police on Saturday. Around 20 cars were torched and four people arrested.

Meanwhile, police union chief David Callu told French TV station BFMTV that violence had spread to the neighbouring towns of Élancourt and Guyancourt over the weekend.

Veil ban

Since April 2011, France has had a ban against full facial veils, outraging many in its Muslim community.

Violations are punishable by a fine of up to 150 euros or mandatory citizenship training.

About 300 women were caught breaking the veil law in the first year it was in force, authorities have said.

A similar outbreak of unrest occurred last month when authorities stopped a 25-year-old woman in Argenteuil, a suburb north-west of Paris, for wearing a full-face veil, or niqab.

An angry crowd gathered and police later fired tear gas and rubber bullets in order to disperse them.